Answer:
People breathe oxygen in and carbon dioxide out, but for a plant to make carbohydrates, the leaves take in carbon dioxide through the stomata on the leaf surfaces. From the stomata, the mesophyll cells use the carbon dioxide to combine it with water and light for photosynthesis.
Answer:
2. muscular system and cardiovascular system
Answer: Option b
Explanation:In chemistry,
before any reaction would occurs, reactat must be able to overcome some certain amount of energy which is called the activation. The activation energy is usually the heat that is suppled.it is also refered to as the minimum energy needed before any reaction can take place. For reaction to take place, there must be an equilibrium( at constant temperature and pressure.
A vaccine works by training the immune system to recognize and combat pathogens, either viruses or bacteria.
